staging:iio: Move ad7793 driver out of staging

The driver does not expose any custom API to userspace and none of the standard
static code checker tools report any issues, so move it out of staging.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

3 files changed, 704 insertions, 0 deletions

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index cd5eed60be2..408557b0244 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -42,6 +42,18 @@ config AD7791
 	  To compile this driver as a module, choose M here: the module will be
 	  called ad7791.
 
+config AD7793
+	tristate "Analog Devices AD7793 and similar ADCs driver"
+	depends on SPI
+	select AD_SIGMA_DELTA
+	help
+	  Say yes here to build support for Analog Devices AD7785, AD7792, AD7793,
+	  AD7794 and AD7795 SPI analog to digital converters (ADC).
+	  If unsure, say N (but it's safe to say "Y").
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called AD7793.
+
 config AD7476
 	tristate "Analog Devices AD7476 and similar 1-channel ADCs driver"
 	depends on SPI
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 3256dc64a46..78202d9eb96 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -7,6 +7,7 @@ obj-$(CONFIG_AD7266) += ad7266.o
 obj-$(CONFIG_AD7298) += ad7298.o
 obj-$(CONFIG_AD7476) += ad7476.o
 obj-$(CONFIG_AD7791) += ad7791.o
+obj-$(CONFIG_AD7793) += ad7793.o
 obj-$(CONFIG_AD7887) += ad7887.o
 obj-$(CONFIG_AT91_ADC) += at91_adc.o
 obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o
diff --git a/drivers/iio/adc/ad7793.c b/drivers/iio/adc/ad7793.c
new file mode 100644
index 00000000000..a109e686b9f
--- /dev/null
+++ b/drivers/iio/adc/ad7793.c
@@ -0,0 +1,691 @@
+/*
+ * AD7785/AD7792/AD7793/AD7794/AD7795 SPI ADC driver
+ *
+ * Copyright 2011-2012 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/spi/spi.h>
+#include <linux/regulator/consumer.h>
+#include <linux/err.h>
+#include <linux/sched.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/adc/ad_sigma_delta.h>
+#include <linux/platform_data/ad7793.h>
+
+/* Registers */
+#define AD7793_REG_COMM		0 /* Communications Register (WO, 8-bit) */
+#define AD7793_REG_STAT		0 /* Status Register	     (RO, 8-bit) */
+#define AD7793_REG_MODE		1 /* Mode Register	     (RW, 16-bit */
+#define AD7793_REG_CONF		2 /* Configuration Register  (RW, 16-bit) */
+#define AD7793_REG_DATA		3 /* Data Register	     (RO, 16-/24-bit) */
+#define AD7793_REG_ID		4 /* ID Register	     (RO, 8-bit) */
+#define AD7793_REG_IO		5 /* IO Register	     (RO, 8-bit) */
+#define AD7793_REG_OFFSET	6 /* Offset Register	     (RW, 16-bit
+				   * (AD7792)/24-bit (AD7793)) */
+#define AD7793_REG_FULLSALE	7 /* Full-Scale Register
+				   * (RW, 16-bit (AD7792)/24-bit (AD7793)) */
+
+/* Communications Register Bit Designations (AD7793_REG_COMM) */
+#define AD7793_COMM_WEN		(1 << 7) /* Write Enable */
+#define AD7793_COMM_WRITE	(0 << 6) /* Write Operation */
+#define AD7793_COMM_READ	(1 << 6) /* Read Operation */
+#define AD7793_COMM_ADDR(x)	(((x) & 0x7) << 3) /* Register Address */
+#define AD7793_COMM_CREAD	(1 << 2) /* Continuous Read of Data Register */
+
+/* Status Register Bit Designations (AD7793_REG_STAT) */
+#define AD7793_STAT_RDY		(1 << 7) /* Ready */
+#define AD7793_STAT_ERR		(1 << 6) /* Error (Overrange, Underrange) */
+#define AD7793_STAT_CH3		(1 << 2) /* Channel 3 */
+#define AD7793_STAT_CH2		(1 << 1) /* Channel 2 */
+#define AD7793_STAT_CH1		(1 << 0) /* Channel 1 */
+
+/* Mode Register Bit Designations (AD7793_REG_MODE) */
+#define AD7793_MODE_SEL(x)	(((x) & 0x7) << 13) /* Operation Mode Select */
+#define AD7793_MODE_SEL_MASK	(0x7 << 13) /* Operation Mode Select mask */
+#define AD7793_MODE_CLKSRC(x)	(((x) & 0x3) << 6) /* ADC Clock Source Select */
+#define AD7793_MODE_RATE(x)	((x) & 0xF) /* Filter Update Rate Select */
+
+#define AD7793_MODE_CONT		0 /* Continuous Conversion Mode */
+#define AD7793_MODE_SINGLE		1 /* Single Conversion Mode */
+#define AD7793_MODE_IDLE		2 /* Idle Mode */
+#define AD7793_MODE_PWRDN		3 /* Power-Down Mode */
+#define AD7793_MODE_CAL_INT_ZERO	4 /* Internal Zero-Scale Calibration */
+#define AD7793_MODE_CAL_INT_FULL	5 /* Internal Full-Scale Calibration */
+#define AD7793_MODE_CAL_SYS_ZERO	6 /* System Zero-Scale Calibration */
+#define AD7793_MODE_CAL_SYS_FULL	7 /* System Full-Scale Calibration */
+
+#define AD7793_CLK_INT		0 /* Internal 64 kHz Clock not
+				   * available at the CLK pin */
+#define AD7793_CLK_INT_CO	1 /* Internal 64 kHz Clock available
+				   * at the CLK pin */
+#define AD7793_CLK_EXT		2 /* External 64 kHz Clock */
+#define AD7793_CLK_EXT_DIV2	3 /* External Clock divided by 2 */
+
+/* Configuration Register Bit Designations (AD7793_REG_CONF) */
+#define AD7793_CONF_VBIAS(x)	(((x) & 0x3) << 14) /* Bias Voltage
+						     * Generator Enable */
+#define AD7793_CONF_BO_EN	(1 << 13) /* Burnout Current Enable */
+#define AD7793_CONF_UNIPOLAR	(1 << 12) /* Unipolar/Bipolar Enable */
+#define AD7793_CONF_BOOST	(1 << 11) /* Boost Enable */
+#define AD7793_CONF_GAIN(x)	(((x) & 0x7) << 8) /* Gain Select */
+#define AD7793_CONF_REFSEL(x)	((x) << 6) /* INT/EXT Reference Select */
+#define AD7793_CONF_BUF		(1 << 4) /* Buffered Mode Enable */
+#define AD7793_CONF_CHAN(x)	((x) & 0xf) /* Channel select */
+#define AD7793_CONF_CHAN_MASK	0xf /* Channel select mask */
+
+#define AD7793_CH_AIN1P_AIN1M	0 /* AIN1(+) - AIN1(-) */
+#define AD7793_CH_AIN2P_AIN2M	1 /* AIN2(+) - AIN2(-) */
+#define AD7793_CH_AIN3P_AIN3M	2 /* AIN3(+) - AIN3(-) */
+#define AD7793_CH_AIN1M_AIN1M	3 /* AIN1(-) - AIN1(-) */
+#define AD7793_CH_TEMP		6 /* Temp Sensor */
+#define AD7793_CH_AVDD_MONITOR	7 /* AVDD Monitor */
+
+#define AD7795_CH_AIN4P_AIN4M	4 /* AIN4(+) - AIN4(-) */
+#define AD7795_CH_AIN5P_AIN5M	5 /* AIN5(+) - AIN5(-) */
+#define AD7795_CH_AIN6P_AIN6M	6 /* AIN6(+) - AIN6(-) */
+#define AD7795_CH_AIN1M_AIN1M	8 /* AIN1(-) - AIN1(-) */
+
+/* ID Register Bit Designations (AD7793_REG_ID) */
+#define AD7785_ID		0xB
+#define AD7792_ID		0xA
+#define AD7793_ID		0xB
+#define AD7794_ID		0xF
+#define AD7795_ID		0xF
+#define AD7793_ID_MASK		0xF
+
+/* IO (Excitation Current Sources) Register Bit Designations (AD7793_REG_IO) */
+#define AD7793_IO_IEXC1_IOUT1_IEXC2_IOUT2	0 /* IEXC1 connect to IOUT1,
+						   * IEXC2 connect to IOUT2 */
+#define AD7793_IO_IEXC1_IOUT2_IEXC2_IOUT1	1 /* IEXC1 connect to IOUT2,
+						   * IEXC2 connect to IOUT1 */
+#define AD7793_IO_IEXC1_IEXC2_IOUT1		2 /* Both current sources
+						   * IEXC1,2 connect to IOUT1 */
+#define AD7793_IO_IEXC1_IEXC2_IOUT2		3 /* Both current sources
+						   * IEXC1,2 connect to IOUT2 */
+
+#define AD7793_IO_IXCEN_10uA	(1 << 0) /* Excitation Current 10uA */
+#define AD7793_IO_IXCEN_210uA	(2 << 0) /* Excitation Current 210uA */
+#define AD7793_IO_IXCEN_1mA	(3 << 0) /* Excitation Current 1mA */
+
+/* NOTE:
+ * The AD7792/AD7793 features a dual use data out ready DOUT/RDY output.
+ * In order to avoid contentions on the SPI bus, it's therefore necessary
+ * to use spi bus locking.
+ *
+ * The DOUT/RDY output must also be wired to an interrupt capable GPIO.
+ */
+
+struct ad7793_chip_info {
+	unsigned int id;
+	const struct iio_chan_spec *channels;
+	unsigned int num_channels;
+};
+
+struct ad7793_state {
+	const struct ad7793_chip_info	*chip_info;
+	struct regulator		*reg;
+	u16				int_vref_mv;
+	u16				mode;
+	u16				conf;
+	u32				scale_avail[8][2];
+
+	struct ad_sigma_delta		sd;
+
+};
+
+enum ad7793_supported_device_ids {
+	ID_AD7785,
+	ID_AD7792,
+	ID_AD7793,
+	ID_AD7794,
+	ID_AD7795,
+};
+
+static struct ad7793_state *ad_sigma_delta_to_ad7793(struct ad_sigma_delta *sd)
+{
+	return container_of(sd, struct ad7793_state, sd);
+}
+
+static int ad7793_set_channel(struct ad_sigma_delta *sd, unsigned int channel)
+{
+	struct ad7793_state *st = ad_sigma_delta_to_ad7793(sd);
+
+	st->conf &= ~AD7793_CONF_CHAN_MASK;
+	st->conf |= AD7793_CONF_CHAN(channel);
+
+	return ad_sd_write_reg(&st->sd, AD7793_REG_CONF, 2, st->conf);
+}
+
+static int ad7793_set_mode(struct ad_sigma_delta *sd,
+			   enum ad_sigma_delta_mode mode)
+{
+	struct ad7793_state *st = ad_sigma_delta_to_ad7793(sd);
+
+	st->mode &= ~AD7793_MODE_SEL_MASK;
+	st->mode |= AD7793_MODE_SEL(mode);
+
+	return ad_sd_write_reg(&st->sd, AD7793_REG_MODE, 2, st->mode);
+}
+
+static const struct ad_sigma_delta_info ad7793_sigma_delta_info = {
+	.set_channel = ad7793_set_channel,
+	.set_mode = ad7793_set_mode,
+	.has_registers = true,
+	.addr_shift = 3,
+	.read_mask = BIT(6),
+};
+
+static const struct ad_sd_calib_data ad7793_calib_arr[6] = {
+	{AD7793_MODE_CAL_INT_ZERO, AD7793_CH_AIN1P_AIN1M},
+	{AD7793_MODE_CAL_INT_FULL, AD7793_CH_AIN1P_AIN1M},
+	{AD7793_MODE_CAL_INT_ZERO, AD7793_CH_AIN2P_AIN2M},
+	{AD7793_MODE_CAL_INT_FULL, AD7793_CH_AIN2P_AIN2M},
+	{AD7793_MODE_CAL_INT_ZERO, AD7793_CH_AIN3P_AIN3M},
+	{AD7793_MODE_CAL_INT_FULL, AD7793_CH_AIN3P_AIN3M}
+};
+
+static int ad7793_calibrate_all(struct ad7793_state *st)
+{
+	return ad_sd_calibrate_all(&st->sd, ad7793_calib_arr,
+				   ARRAY_SIZE(ad7793_calib_arr));
+}
+
+static int ad7793_setup(struct iio_dev *indio_dev,
+	const struct ad7793_platform_data *pdata,
+	unsigned int vref_mv)
+{
+	struct ad7793_state *st = iio_priv(indio_dev);
+	int i, ret = -1;
+	unsigned long long scale_uv;
+	u32 id;
+
+	if ((pdata->current_source_direction == AD7793_IEXEC1_IEXEC2_IOUT1 ||
+		pdata->current_source_direction == AD7793_IEXEC1_IEXEC2_IOUT2) &&
+		((pdata->exitation_current != AD7793_IX_10uA) &&
+		(pdata->exitation_current != AD7793_IX_210uA)))
+		return -EINVAL;
+
+	/* reset the serial interface */
+	ret = spi_write(st->sd.spi, (u8 *)&ret, sizeof(ret));
+	if (ret < 0)
+		goto out;
+	usleep_range(500, 2000); /* Wait for at least 500us */
+
+	/* write/read test for device presence */
+	ret = ad_sd_read_reg(&st->sd, AD7793_REG_ID, 1, &id);
+	if (ret)
+		goto out;
+
+	id &= AD7793_ID_MASK;
+
+	if (id != st->chip_info->id) {
+		dev_err(&st->sd.spi->dev, "device ID query failed\n");
+		goto out;
+	}
+
+	st->mode = AD7793_MODE_RATE(1);
+	st->mode |= AD7793_MODE_CLKSRC(pdata->clock_src);
+	st->conf = AD7793_CONF_REFSEL(pdata->refsel);
+	st->conf |= AD7793_CONF_VBIAS(pdata->bias_voltage);
+	if (pdata->buffered)
+		st->conf |= AD7793_CONF_BUF;
+	if (pdata->boost_enable)
+		st->conf |= AD7793_CONF_BOOST;
+	if (pdata->burnout_current)
+		st->conf |= AD7793_CONF_BO_EN;
+	if (pdata->unipolar)
+		st->conf |= AD7793_CONF_UNIPOLAR;
+
+	ret = ad7793_set_mode(&st->sd, AD_SD_MODE_IDLE);
+	if (ret)
+		goto out;
+
+	ret = ad7793_set_channel(&st->sd, 0);
+	if (ret)
+		goto out;
+
+	ret = ad_sd_write_reg(&st->sd, AD7793_REG_IO, 1,
+				   pdata->exitation_current |
+			       (pdata->current_source_direction << 2));
+	if (ret)
+		goto out;
+
+	ret = ad7793_calibrate_all(st);
+	if (ret)
+		goto out;
+
+	/* Populate available ADC input ranges */
+	for (i = 0; i < ARRAY_SIZE(st->scale_avail); i++) {
+		scale_uv = ((u64)vref_mv * 100000000)
+			>> (st->chip_info->channels[0].scan_type.realbits -
+			(!!(st->conf & AD7793_CONF_UNIPOLAR) ? 0 : 1));
+		scale_uv >>= i;
+
+		st->scale_avail[i][1] = do_div(scale_uv, 100000000) * 10;
+		st->scale_avail[i][0] = scale_uv;
+	}
+
+	return 0;
+out:
+	dev_err(&st->sd.spi->dev, "setup failed\n");
+	return ret;
+}
+
+static const u16 sample_freq_avail[16] = {0, 470, 242, 123, 62, 50, 39, 33, 19,
+					  17, 16, 12, 10, 8, 6, 4};
+
+static ssize_t ad7793_read_frequency(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct ad7793_state *st = iio_priv(indio_dev);
+
+	return sprintf(buf, "%d\n",
+		       sample_freq_avail[AD7793_MODE_RATE(st->mode)]);
+}
+
+static ssize_t ad7793_write_frequency(struct device *dev,
+		struct device_attribute *attr,
+		const char *buf,
+		size_t len)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct ad7793_state *st = iio_priv(indio_dev);
+	long lval;
+	int i, ret;
+
+	mutex_lock(&indio_dev->mlock);
+	if (iio_buffer_enabled(indio_dev)) {
+		mutex_unlock(&indio_dev->mlock);
+		return -EBUSY;
+	}
+	mutex_unlock(&indio_dev->mlock);
+
+	ret = kstrtol(buf, 10, &lval);
+	if (ret)
+		return ret;
+
+	ret = -EINVAL;
+
+	for (i = 0; i < ARRAY_SIZE(sample_freq_avail); i++)
+		if (lval == sample_freq_avail[i]) {
+			mutex_lock(&indio_dev->mlock);
+			st->mode &= ~AD7793_MODE_RATE(-1);
+			st->mode |= AD7793_MODE_RATE(i);
+			ad_sd_write_reg(&st->sd, AD7793_REG_MODE,
+					 sizeof(st->mode), st->mode);
+			mutex_unlock(&indio_dev->mlock);
+			ret = 0;
+		}
+
+	return ret ? ret : len;
+}
+
+static IIO_DEV_ATTR_SAMP_FREQ(S_IWUSR | S_IRUGO,
+		ad7793_read_frequency,
+		ad7793_write_frequency);
+
+static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(
+	"470 242 123 62 50 39 33 19 17 16 12 10 8 6 4");
+
+static ssize_t ad7793_show_scale_available(struct device *dev,
+			struct device_attribute *attr, char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct ad7793_state *st = iio_priv(indio_dev);
+	int i, len = 0;
+
+	for (i = 0; i < ARRAY_SIZE(st->scale_avail); i++)
+		len += sprintf(buf + len, "%d.%09u ", st->scale_avail[i][0],
+			       st->scale_avail[i][1]);
+
+	len += sprintf(buf + len, "\n");
+
+	return len;
+}
+
+static IIO_DEVICE_ATTR_NAMED(in_m_in_scale_available,
+		in_voltage-voltage_scale_available, S_IRUGO,
+		ad7793_show_scale_available, NULL, 0);
+
+static struct attribute *ad7793_attributes[] = {
+	&iio_dev_attr_sampling_frequency.dev_attr.attr,
+	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
+	&iio_dev_attr_in_m_in_scale_available.dev_attr.attr,
+	NULL
+};
+
+static const struct attribute_group ad7793_attribute_group = {
+	.attrs = ad7793_attributes,
+};
+
+static int ad7793_read_raw(struct iio_dev *indio_dev,
+			   struct iio_chan_spec const *chan,
+			   int *val,
+			   int *val2,
+			   long m)
+{
+	struct ad7793_state *st = iio_priv(indio_dev);
+	int ret;
+	unsigned long long scale_uv;
+	bool unipolar = !!(st->conf & AD7793_CONF_UNIPOLAR);
+
+	switch (m) {
+	case IIO_CHAN_INFO_RAW:
+		ret = ad_sigma_delta_single_conversion(indio_dev, chan, val);
+		if (ret < 0)
+			return ret;
+
+		return IIO_VAL_INT;
+
+	case IIO_CHAN_INFO_SCALE:
+		switch (chan->type) {
+		case IIO_VOLTAGE:
+			if (chan->differential) {
+				*val = st->
+					scale_avail[(st->conf >> 8) & 0x7][0];
+				*val2 = st->
+					scale_avail[(st->conf >> 8) & 0x7][1];
+				return IIO_VAL_INT_PLUS_NANO;
+			} else {
+				/* 1170mV / 2^23 * 6 */
+				scale_uv = (1170ULL * 1000000000ULL * 6ULL);
+			}
+			break;
+		case IIO_TEMP:
+				/* 1170mV / 0.81 mV/C / 2^23 */
+				scale_uv = 1444444444444444ULL;
+			break;
+		default:
+			return -EINVAL;
+		}
+
+		scale_uv >>= (chan->scan_type.realbits - (unipolar ? 0 : 1));
+		*val = 0;
+		*val2 = scale_uv;
+		return IIO_VAL_INT_PLUS_NANO;
+	case IIO_CHAN_INFO_OFFSET:
+		if (!unipolar)
+			*val = -(1 << (chan->scan_type.realbits - 1));
+		else
+			*val = 0;
+
+		/* Kelvin to Celsius */
+		if (chan->type == IIO_TEMP) {
+			unsigned long long offset;
+			unsigned int shift;
+
+			shift = chan->scan_type.realbits - (unipolar ? 0 : 1);
+			offset = 273ULL << shift;
+			do_div(offset, 1444);
+			*val -= offset;
+		}
+		return IIO_VAL_INT;
+	}
+	return -EINVAL;
+}
+
+static int ad7793_write_raw(struct iio_dev *indio_dev,
+			       struct iio_chan_spec const *chan,
+			       int val,
+			       int val2,
+			       long mask)
+{
+	struct ad7793_state *st = iio_priv(indio_dev);
+	int ret, i;
+	unsigned int tmp;
+
+	mutex_lock(&indio_dev->mlock);
+	if (iio_buffer_enabled(indio_dev)) {
+		mutex_unlock(&indio_dev->mlock);
+		return -EBUSY;
+	}
+
+	switch (mask) {
+	case IIO_CHAN_INFO_SCALE:
+		ret = -EINVAL;
+		for (i = 0; i < ARRAY_SIZE(st->scale_avail); i++)
+			if (val2 == st->scale_avail[i][1]) {
+				ret = 0;
+				tmp = st->conf;
+				st->conf &= ~AD7793_CONF_GAIN(-1);
+				st->conf |= AD7793_CONF_GAIN(i);
+
+				if (tmp == st->conf)
+					break;
+
+				ad_sd_write_reg(&st->sd, AD7793_REG_CONF,
+						sizeof(st->conf), st->conf);
+				ad7793_calibrate_all(st);
+				break;
+			}
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	mutex_unlock(&indio_dev->mlock);
+	return ret;
+}
+
+static int ad7793_write_raw_get_fmt(struct iio_dev *indio_dev,
+			       struct iio_chan_spec const *chan,
+			       long mask)
+{
+	return IIO_VAL_INT_PLUS_NANO;
+}
+
+static const struct iio_info ad7793_info = {
+	.read_raw = &ad7793_read_raw,
+	.write_raw = &ad7793_write_raw,
+	.write_raw_get_fmt = &ad7793_write_raw_get_fmt,
+	.attrs = &ad7793_attribute_group,
+	.validate_trigger = ad_sd_validate_trigger,
+	.driver_module = THIS_MODULE,
+};
+
+#define DECLARE_AD7793_CHANNELS(_name, _b, _sb, _s) \
+const struct iio_chan_spec _name##_channels[] = { \
+	AD_SD_DIFF_CHANNEL(0, 0, 0, AD7793_CH_AIN1P_AIN1M, (_b), (_sb), (_s)), \
+	AD_SD_DIFF_CHANNEL(1, 1, 1, AD7793_CH_AIN2P_AIN2M, (_b), (_sb), (_s)), \
+	AD_SD_DIFF_CHANNEL(2, 2, 2, AD7793_CH_AIN3P_AIN3M, (_b), (_sb), (_s)), \
+	AD_SD_SHORTED_CHANNEL(3, 0, AD7793_CH_AIN1M_AIN1M, (_b), (_sb), (_s)), \
+	AD_SD_TEMP_CHANNEL(4, AD7793_CH_TEMP, (_b), (_sb), (_s)), \
+	AD_SD_SUPPLY_CHANNEL(5, 3, AD7793_CH_AVDD_MONITOR, (_b), (_sb), (_s)), \
+	IIO_CHAN_SOFT_TIMESTAMP(6), \
+}
+
+#define DECLARE_AD7795_CHANNELS(_name, _b, _sb) \
+const struct iio_chan_spec _name##_channels[] = { \
+	AD_SD_DIFF_CHANNEL(0, 0, 0, AD7793_CH_AIN1P_AIN1M, (_b), (_sb), 0), \
+	AD_SD_DIFF_CHANNEL(1, 1, 1, AD7793_CH_AIN2P_AIN2M, (_b), (_sb), 0), \
+	AD_SD_DIFF_CHANNEL(2, 2, 2, AD7793_CH_AIN3P_AIN3M, (_b), (_sb), 0), \
+	AD_SD_DIFF_CHANNEL(3, 3, 3, AD7795_CH_AIN4P_AIN4M, (_b), (_sb), 0), \
+	AD_SD_DIFF_CHANNEL(4, 4, 4, AD7795_CH_AIN5P_AIN5M, (_b), (_sb), 0), \
+	AD_SD_DIFF_CHANNEL(5, 5, 5, AD7795_CH_AIN6P_AIN6M, (_b), (_sb), 0), \
+	AD_SD_SHORTED_CHANNEL(6, 0, AD7795_CH_AIN1M_AIN1M, (_b), (_sb), 0), \
+	AD_SD_TEMP_CHANNEL(7, AD7793_CH_TEMP, (_b), (_sb), 0), \
+	AD_SD_SUPPLY_CHANNEL(8, 3, AD7793_CH_AVDD_MONITOR, (_b), (_sb), 0), \
+	IIO_CHAN_SOFT_TIMESTAMP(9), \
+}
+
+static DECLARE_AD7793_CHANNELS(ad7785, 20, 32, 4);
+static DECLARE_AD7793_CHANNELS(ad7792, 16, 32, 0);
+static DECLARE_AD7793_CHANNELS(ad7793, 24, 32, 0);
+static DECLARE_AD7795_CHANNELS(ad7794, 16, 32);
+static DECLARE_AD7795_CHANNELS(ad7795, 24, 32);
+
+static const struct ad7793_chip_info ad7793_chip_info_tbl[] = {
+	[ID_AD7785] = {
+		.id = AD7785_ID,
+		.channels = ad7785_channels,
+		.num_channels = ARRAY_SIZE(ad7785_channels),
+	},
+	[ID_AD7792] = {
+		.id = AD7792_ID,
+		.channels = ad7792_channels,
+		.num_channels = ARRAY_SIZE(ad7792_channels),
+	},
+	[ID_AD7793] = {
+		.id = AD7793_ID,
+		.channels = ad7793_channels,
+		.num_channels = ARRAY_SIZE(ad7793_channels),
+	},
+	[ID_AD7794] = {
+		.id = AD7794_ID,
+		.channels = ad7794_channels,
+		.num_channels = ARRAY_SIZE(ad7794_channels),
+	},
+	[ID_AD7795] = {
+		.id = AD7795_ID,
+		.channels = ad7795_channels,
+		.num_channels = ARRAY_SIZE(ad7795_channels),
+	},
+};
+
+static int ad7793_probe(struct spi_device *spi)
+{
+	const struct ad7793_platform_data *pdata = spi->dev.platform_data;
+	struct ad7793_state *st;
+	struct iio_dev *indio_dev;
+	int ret, vref_mv = 0;
+
+	if (!pdata) {
+		dev_err(&spi->dev, "no platform data?\n");
+		return -ENODEV;
+	}
+
+	if (!spi->irq) {
+		dev_err(&spi->dev, "no IRQ?\n");
+		return -ENODEV;
+	}
+
+	indio_dev = iio_device_alloc(sizeof(*st));
+	if (indio_dev == NULL)
+		return -ENOMEM;
+
+	st = iio_priv(indio_dev);
+
+	ad_sd_init(&st->sd, indio_dev, spi, &ad7793_sigma_delta_info);
+
+	if (pdata->refsel != AD7793_REFSEL_INTERNAL) {
+		st->reg = regulator_get(&spi->dev, "refin");
+		if (IS_ERR(st->reg)) {
+			ret = PTR_ERR(st->reg);
+			goto error_device_free;
+		}
+
+		ret = regulator_enable(st->reg);
+		if (ret)
+			goto error_put_reg;
+
+		vref_mv = regulator_get_voltage(st->reg);
+		if (vref_mv < 0) {
+			ret = vref_mv;
+			goto error_disable_reg;
+		}
+
+		vref_mv /= 1000;
+	} else {
+		vref_mv = 1170; /* Build-in ref */
+	}
+
+	st->chip_info =
+		&ad7793_chip_info_tbl[spi_get_device_id(spi)->driver_data];
+
+	spi_set_drvdata(spi, indio_dev);
+
+	indio_dev->dev.parent = &spi->dev;
+	indio_dev->name = spi_get_device_id(spi)->name;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = st->chip_info->channels;
+	indio_dev->num_channels = st->chip_info->num_channels;
+	indio_dev->info = &ad7793_info;
+
+	ret = ad_sd_setup_buffer_and_trigger(indio_dev);
+	if (ret)
+		goto error_disable_reg;
+
+	ret = ad7793_setup(indio_dev, pdata, vref_mv);
+	if (ret)
+		goto error_remove_trigger;
+
+	ret = iio_device_register(indio_dev);
+	if (ret)
+		goto error_remove_trigger;
+
+	return 0;
+
+error_remove_trigger:
+	ad_sd_cleanup_buffer_and_trigger(indio_dev);
+error_disable_reg:
+	if (pdata->refsel != AD7793_REFSEL_INTERNAL)
+		regulator_disable(st->reg);
+error_put_reg:
+	if (pdata->refsel != AD7793_REFSEL_INTERNAL)
+		regulator_put(st->reg);
+error_device_free:
+	iio_device_free(indio_dev);
+
+	return ret;
+}
+
+static int ad7793_remove(struct spi_device *spi)
+{
+	const struct ad7793_platform_data *pdata = spi->dev.platform_data;
+	struct iio_dev *indio_dev = spi_get_drvdata(spi);
+	struct ad7793_state *st = iio_priv(indio_dev);
+
+	iio_device_unregister(indio_dev);
+	ad_sd_cleanup_buffer_and_trigger(indio_dev);
+
+	if (pdata->refsel != AD7793_REFSEL_INTERNAL) {
+		regulator_disable(st->reg);
+		regulator_put(st->reg);
+	}
+
+	iio_device_free(indio_dev);
+
+	return 0;
+}
+
+static const struct spi_device_id ad7793_id[] = {
+	{"ad7785", ID_AD7785},
+	{"ad7792", ID_AD7792},
+	{"ad7793", ID_AD7793},
+	{"ad7794", ID_AD7794},
+	{"ad7795", ID_AD7795},
+	{}
+};
+MODULE_DEVICE_TABLE(spi, ad7793_id);
+
+static struct spi_driver ad7793_driver = {
+	.driver = {
+		.name	= "ad7793",
+		.owner	= THIS_MODULE,
+	},
+	.probe		= ad7793_probe,
+	.remove		= ad7793_remove,
+	.id_table	= ad7793_id,
+};
+module_spi_driver(ad7793_driver);
+
+MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
+MODULE_DESCRIPTION("Analog Devices AD7793 and simialr ADCs");
+MODULE_LICENSE("GPL v2");